24. 98 Unit 20 The ex-hacker

25. WORD STUDY

26. SPEAKING

28. Semantic groups

29. 8 As all the words listed have been used in previous units, you can again use this task as a revision test or do it as an individual task. Correct in plenary marking each heading on the board, A to E, and filling in the terms below as Ss provide them to you. Advise Ss that keeping a vocabulary notebook divided into semantic fields like this is a sensible way of grouping and hence remembering their growing IT vocabulary.

30. Key 8
    B,A	anti-virus software
    В	backups
    CD,E	bandwidth
    E	browser
    E,D	domain name
    В	encryption
    В	firewalls
    D	FTP
    С	GPS
    D,C,E	IRC
    D,E	ISP
    E	hyperlink
    A	logic bomb
    С	pagers
    В	passwords
    D	router
    A	trigger routine
    A	Trojan
    E,D	URL
    D,C	Usenet
    E	XML

31. Role play

32. 9 Prepare this in pairs where the interviewers work together and the interviewees work together. Then re-pair interviewer + interviewee for the actual task. Allow Ss to add information of their own to the interview.

33. Key 9 (examples only)

1. When did you first become interested in hacking?

2. Why were you arrested?

3. What do you do now?

4. How can you prevent hacking?

5. What do you think of Hollywood hackers?

6. What are safe ways of paying for Internet shopping?

78. WRITING

79. 10 This ties in with Task 1. Ss should exchange texts for their colleagues to comment on and mark any areas they have problems understanding. If Ss have access to a networked computer lab, they can exchange texts electronically, comment and return to the writer.

80. _{UNIT 21}

82. Software Engineering

83. Introduction

84. Software engineering is the discipline of designing high quality software solutions. Software consists of programs (sets of instructions for controlling a computer) and data (the material that has to be processed). Programs are written in computer languages by people called programmers. A systems analyst is a person who designs or modifies information systems to meet users' requirements. This includes investigating feasibility and cost, producing documentation, and testing prototypes of the system. Producing a program, therefore, involves a number of stages including:

85. a clarifying the problem by considering the

86. requirements of the potential users b designing the solution to the problem by

87. first deciding on the overall structure of

88. the solution с coding the program by first choosing an

89. appropriate programming language and

90. inputting the program code d testing and debugging the program

91. (identifying and fixing any problems or

92. faults in the program code) e documenting and maintaining the

93. program including writing instructions for

94. using the program.

96. Systems analysts first need to talk to the people involved in the computing problem, including the people managing the system and the users or potential users of the system. They need to establish factors such as:

97. a the nature of the problem

98. b what systems already exist

99. с to what extent any existing systems are computerised (changed so that they can be operated or controlled using a computer)

100. d what output (the processed data or signals

101. that come out of a computer system) will

102. be required from the system e who will be using the system and what

103. parts of the system they need to be able

104. to use

105. f the computing experience of the staff and what training would be required

106. g what hardware (the physical components of a computer system) already exists and what would need to be added, including the specification of the hardware and whether a network system is required (a system where a number of computers and peripheral devices are connected together).

108. They then have to plan the structure of the solution and check it through with the people involved to make sure it meets their requirements. Next, they have to choose a suitable programming language and write the program (a set of instructions, written in a computer language, that control the behaviour of a computer), continually testing and adapting it until it works to the satisfaction of the customer and users. The system then has to be put into service and the users have to be trained. This involves documenting the program specifications and writing instructions for using the system.

109. Programming languages commonly use different structures for sequencing program instructions, including:

110. a conditional instructions i.e. if a certain condition is true, then process this instruction (if X then Y). Decision tables are used to indicate how a conditional structure will process data. They show all the different inputs that might arise for each condition and the resulting outputs that would be produced by the conditional instruction.

111. b iterations or loop instructions i.e. process these instructions repeatedly until or while a particular condition is true, or false (do... until... or do... while...). Program flowcharts can be used to show the sequence of instructions in a program and are sometimes used for designing parts of programs such as iterations. Pseudocode is a method of writing a description of a computer program using a mixture of natural language and computer language code.

113. There are a large number of computer languages available for use by programmers. Each language is designed for use in solving particular types of problem and therefore has particular strengths and weaknesses. A systems analyst has to decide which language is most appropriate in each situation. Languages such as С++ are particularly suitable for writing systems programs (programs that are used to control the basic functions of a computer system e.g. operating system programs). Languages such as Visual Basic and Pascal are easy to use and are particularly suitable for learning how to program. FORTRAN is designed for solving engineering problems, COBOL for writing business programs, Ada for military purposes, Prolog and LISP for working in artificial intelligence (an area of computing concerned with developing computer programs that perform tasks that can normally only be done

114. using human intelligence). Logo is particularly suited for use by young children. Some languages such as HTML and XML are markup languages rather than programming languages i.e. they use tag codes (labels) for marking text for use in programs such as Web browsers. Languages such as Java and Perl have a number of specialised uses including adding features to Internet connections and webpages (hyperlinked documents).

115. Converting to new computer systems can be done in different ways. Each strategy has its advantages and disadvantages. These include:

116. a direct implementation where the old system is simply removed and the new system installed. In this strategy only one system is used at any one time but there is no fall back (alternative system that can be used if problems occur in the main system) if the new system does not operate properly.

117. b parallel implementation where the old and the new systems are both used at the same time until the users are satisfied that the new system is working properly

118. с phased implementation where the old system is gradually replaced by the new system, one part at a time

119. d pilot implementation where the new system is tried out in one section of the company to make sure that it works as required.

121. OBJECTIVES

122. By the end of this unit, Ss should be better at:

123. • listening for specific information.

124. They should understand and be able to use structures used in programming:

125. • IfX, then Y. Do X until/while Y.

126. They should have a better understanding of terms used in Software Engineering such as: decision table, flowchart, pseudocode and the names of current programming languages.

127. STARTER

128. 1 Do this in small groups. The groups should then agree what each stage means.

129. Keyl

130. d Clarify the problem a Design a solution b Code the program e Test the program

131. с Document and maintain the program

133. 2 The same groups as Task 1 should continue with this task. When they have completed, they should compare with a neighbouring group.

134. Key 2

135. 1 d Clarify objectives and users: Clarify the problem

136. 2e Debug the progranrr.Test the program

137. 3c Write programmer documentation: Document

138. and maintain the program 4a Do a structured walkthrough: Design a solution 5b Select the appropriate programming

139. language: Code the program

140. LISTENING

3. Do this individually, then compare in groups. Make sure all Ss have a list of questions for Task 4.

3. Make sure that Ss know that bookings = reservations and are familiar with other common hotel-related terms such as reception. Play the recording once so that Ss can tick off their list of questions with those asked by the analyst. Get them also to note any questions they had not predicted.

3. Do this individually. Play the recording again, pausing to give time to note the answers after this exchange which is roughly half-way through:

141. A Has the system to print out addressed

142. envelopes? H If it could, that would be very useful.

143. Key 5

1. A simple bookings system.

2. It is not linked to invoicing.

3. Bills for the guests, room bookings on screen and lists of previous guests.

4. Reception staff, the accountant, bar and restaurant staff.

5. The accountant.

6. She does not want unauthorised people to be able to access the accounts and the printers must not be noisy.

7. In addition to the existing PCs at reception and in the office, she will need one for the accountant and one in the bar and restaurant. They will have to be networked. She will need laser printers.

8. The analyst will make a plan to discuss with the hotelier.Then he will make a program to try.

144. LANGUAGE WORK

145. Revision: IfX, then Y

146. This section focuses on structures commonly used in programming. All have been met in earlier units but in different contexts.

147. Write the decision table in the student's book on the board. Demonstrate one of the rules:

148. 1 If a guest stays 3 nights in January and if one night is Sunday, then charge 2 nights at full price and 1 night at half-price.

149. Elicit other rules by giving the //-clause:

2. If a guest stays 3 nights and one night is not Sunday and it is not January, then charge 3 nights at full price.

3. If a guest stays 3 weekday nights in January, then charge 3 nights at full price.

150. 6 Do this individually, then compare answers in pairs.

151. Key б Examples

1. If a guest books bed and breakfast and has no other meals, then charge rate A.

2. If a guest books bed and breakfast and also has lunch, then charge rate A plus menu price less 20%.

3. If a guest books bed and breakfast and also has dinner, then charge rate A plus menu price less 20%.

4. If a guest books half-board and has no other meals, then charge rate 8.

5. If a guest books half-board and has lunch, then charge rate В plus menu price less 20%.

6. If a guest books full board, then charge rate C.

152. Do until, do while

153. 7 Ss will be familiar with these time words from their study of time clauses. Until links an action and the limit of that action. While links actions or states happening at the same time. Use the textbook examples to illustrate the structures when used to describe loops in flowcharts; then set Task 7 for individual work.

154. Key 7

1. Calculate all sales until there are no more sales.

2. Search for records containing the term while there are still records containing the term.

3. Total extra items while extra items remain.

4. Search member records until there are no more records.

5. Print all addresses while there are still addresses available.

6. Display client names until there are no names remaining.

7. List ail guests until there are no guests left.

8. Total monthly sales until there are no more sales for the current year.

155. 8 Do this individually. Then ask selected Ss to explain each step orally as a means of checking the task. Advanced Ss can draw a flowchart of their own for their partners to explain orally.

156. Key 8

157. First input the room number.Then set the total to zero. Next, set the VAT to zero.Then set the count to zero. After that, read a record. If it is for this number of room then, if the count is zero, print the guest details. Next, add the record amount to the total.Then add one to the count. After that, print the record details. If there are more records, then read another record. If there are not more records, then, if the count is greater than zero, calculate the VAT.Then calculate the gross. Next print the total. After that, print the VAT. Finally, print the gross.

158. SPEAKING

159. 9 Work in pairs, then compare answers with another pair.

160. Key 9
     1	Logo
     2	Visual Basic
     3	FORTRAN
     4	HTML
     5	С++
     6	Ada
     7	COBOL
     8	XML
     9	Prolog, LISP
     10	Pascal, Visual Basic
     11	Visual Basic, С++
     12	Java, Perl

161. WRITING

162. Converting to a new system

163. 10 For individual work. Ss should exchange completed texts with each acting as critical reader for the other. As before, the readers should simply underline with a pencil any area where they feel the meaning of the text is unclear and return it to the writer for action.

164. Key 10

2. Parallel implementation: Parallel implementation means that both systems run at the same time for a periodThe advantage is that if the new system does not operate properly, the old system is available as a fallback.The disadvantage is that two systems have to be maintained.

3. Phased implementation: Phased implementation is when parts of the system are converted separately.This may be done gradually or in groups.The advantage is that people can gradually get used to the new system and certain problems can be dealt with as they arise.The disadvantage is that this method is more complex and time-consuming. In addition, there may be problems of incompatibility between the old and new systems.

2. UNIT 21 Software Engineering 103

2. 4 Pilot implementation: Pilot implementation is when the new system is piloted in part of the company before extending it to the whole company.The advantage is that problems can be identified and solved before the new system is implemented throughout the company.The disadvantage is that it takes longer to introduce the new system.

3. SPECIALIST READING

4. Key A

1. simplifies the handling of multimedia applications; program code is more intuitive and reusable

2. encapsulation; inheritance; polymorphism

3. sound; video; text; graphics

4. right; equilateral; isosceles

5. encapsulation

6. square

7. has 4 sides; contains 4 right angles

8. program development; program maintenance

2. Key В

1. a vi b i с v d ii e vii f iii g iv

2. Encapsulation, inheritance and polymorphism are key features of object-oriented programming. Encapsulation allows data and program instructions to be bundled together in modules called objects. Inheritance means that specific instances of a class of objects inherit the properties of the class of objects. Polymorphism means that instructions are treated differently by different objects.The combination of these key features of OOP means that program code is reusable.This speeds up development and maintenance of programs.